labs

ABS(3)                     Linux Programmer's Manual                    ABS(3)

NAME
       abs, labs, llabs, imaxabs - compute the absolute value of an integer

SYNOPSIS
       #include <stdlib.h>

       int abs(int j);
       long int labs(long int j);
       long long int llabs(long long int j);

       #include <inttypes.h>

       intmax_t imaxabs(intmax_t j);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       llabs():
           _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L

DESCRIPTION
       The  abs() function computes the absolute value of the integer argument
       j.  The labs(), llabs() and imaxabs() functions  compute  the  absolute
       value  of  the argument j of the appropriate integer type for the func-
       tion.

RETURN VALUE
       Returns the absolute value of the integer argument, of the  appropriate
       integer type for the function.

ATTRIBUTES
       For  an  explanation  of  the  terms  used  in  this  section,  see at-
       tributes(7).

       +-------------------+---------------+---------+
       |Interface          | Attribute     | Value   |
       +-------------------+---------------+---------+
       |abs(), labs(),     | Thread safety | MT-Safe |
       |llabs(), imaxabs() |               |         |
       +-------------------+---------------+---------+
CONFORMING TO
       POSIX.1-2001,  POSIX.1-2008,  C99, SVr4, 4.3BSD.  C89 only includes the
       abs() and labs() functions; the functions llabs()  and  imaxabs()  were
       added in C99.

NOTES
       Trying  to  take the absolute value of the most negative integer is not
       defined.

       The llabs() function is included in glibc since version 2.0.  The imax-
       abs() function is included in glibc since version 2.1.1.

       For   llabs()   to   be   declared,  it  may  be  necessary  to  define
       _ISOC99_SOURCE or _ISOC9X_SOURCE (depending on the  version  of  glibc)
       before including any standard headers.

       By  default, GCC handles abs(), labs(), and (since GCC 3.0) llabs() and
       imaxabs() as built-in functions.

SEE ALSO
       cabs(3), ceil(3), fabs(3), floor(3), rint(3)

COLOPHON
       This page is part of release 5.05 of the Linux  man-pages  project.   A
       description  of  the project, information about reporting bugs, and the
       latest    version    of    this    page,    can     be     found     at
       https://www.kernel.org/doc/man-pages/.

GNU                               2016-03-15                            ABS(3)